Material for use in a TMR read gap without adversely affecting the TMR effect

ABSTRACT

Structures and methods for fabrication servo and data heads of tape modules are provided. The servo head may have two shield layers spaced apart by a plurality of gap layers and a sensor. Similarly, the data head may have two shield layers spaced apart by a plurality of gap layers and a sensor. The distance between the shield layers of the servo head may be greater than the distance between the shield layers of the data head. The material of the gap layers may include tantalum or an alloy of nickel and chromium. The material for the gap layers permits deposition of gap layers with sufficiently small surface roughness to prevent distortion of the tape module and increase the stability of the tape module operation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/916,256, filed Oct. 29, 2010, which application claimsbenefit of U.S. Provisional Patent Application Ser. No. 61/326,607,filed Apr. 21, 2010, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

Embodiments of the present invention generally relate to tape modulesused for magnetic recording on tapes, and more specifically tofabrication of servo and data head structures of a tape module.

Description of the Related Art

Tape modules are used to record and readback information on tapes bymagnetic processes. The tape modules use servo heads to read servotracks to align the heads for reading data stored on data tracks. Theservo heads and data heads are typically formed using a sensor disposedbetween two shield layers and directly contacting the two shield layers.However, current servo and data head designs do not provide adequatereadback in newer tape designs that require higher data densities aswell as different servo track and data track densities. Additionally,the industry is moving to a tunneling magnetoresistive (TMR) sensor,which has a read gap defined by the TMR film. With current tapedensities, a wider read gap is needed in both the data and servo heads,and additionally, the respective gaps must be unique to one another.

It is desirable to provide new head structures and processes for formingthe same that allow for achieving higher recording area density than iscurrently available for tape modules.

SUMMARY OF THE INVENTION

Structures and methods for fabrication of servo and data heads of tapemodules are provided. The servo head may have two shield layers spacedapart by a plurality of gap layers and a sensor. Similarly, the datahead may have two shield layers spaced apart by a plurality of gaplayers and a sensor. The distance between the shield layers of the servohead may be greater than the distance between the shield layers of thedata head. The material of the gap layers may include tantalum or analloy of nickel and chromium. The material for the gap layers permitsdeposition of gap layers with sufficiently small surface roughness toprevent distortion of the TMR barrier and increase the stability of thetape module operation.

Embodiments of the present invention generally relate to tape modules,and more specifically to fabrication of servo and data head structuresof a tape module. In one embodiment, a tape module is disclosed. Thetape module includes a servo head structure. The servo head structureincludes a first servo head shield layer, a first electricallyconductive servo head gap layer disposed on the first servo head shieldlayer, and a second electrically conductive servo head gap layerdisposed on the first electrically conductive servo head gap layer. Theservo head structure also includes a servo head dielectric layerdisposed on the second electrically conductive servo head gap layer anda servo head sensor disposed on the second electrically conductive servohead gap layer. The servo head also includes a third electricallyconductive servo head gap layer disposed on the servo head dielectriclayer and servo head sensor, a fourth electrically conductive servo headgap layer disposed on the third electrically conductive servo head gaplayer, and a second servo head shield layer disposed on the fourthelectrically conductive servo head gap layer.

In another embodiment, tape module is disclosed. The tape moduleincludes a data head structure. The data head structure includes a firstshield layer, a first gap layer disposed on the first shield layer, adielectric layer disposed on the first gap layer, and a sensor disposedon the first gap layer. The data head structure also includes a secondgap layer disposed on the dielectric layer and sensor, and a secondshield layer disposed on the second gap layer.

In another embodiment, a method for forming a tape module is disclosed.The method includes forming a servo head structure on a substrate. Theservo head structure is formed by a method that includes depositing afirst servo head shield layer on the substrate, depositing a firstelectrically conductive servo head gap layer on the first servo headshield layer, depositing a second electrically conductive servo head gaplayer on the first electrically conductive servo head gap layer, andforming a servo head sensor on the second electrically conductive servohead gap layer. The method also includes depositing a servo headdielectric layer on the second electrically conductive servo head gaplayer, depositing a third electrically conductive servo head gap layeron the servo head dielectric layer and servo head sensor, depositing afourth electrically conductive servo head gap layer on the thirdelectrically conductive servo head gap layer, and depositing a secondservo head shield layer on the fourth electrically conductive servo headgap layer.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A is a cross sectional view of a servo head and a data headaccording to one embodiment of the present invention;

FIG. 1B is a cross sectional view of a servo head and a data headaccording to another embodiment of the present invention;

FIGS. 2A-2H illustrate a series of top plan cross sectional views of thesteps to form the servo head and the data head according to theembodiment of FIG. 1A;

FIGS. 3A-3F illustrate a series of cross sectional views of the steps toform the servo head and the data head according to the embodiment ofFIG. 1A; and

FIGS. 4A-4F illustrate a series of cross sectional views of the steps toform the servo head according to the embodiment of FIG. 1B.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

In the following, reference is made to embodiments of the invention.However, it should be understood that the invention is not limited tospecific described embodiments. Instead, any combination of thefollowing features and elements, whether related to differentembodiments or not, is contemplated to implement and practice theinvention. Furthermore, although embodiments of the invention mayachieve advantages over other possible solutions and/or over the priorart, whether or not a particular advantage is achieved by a givenembodiment is not limiting of the invention. Thus, the followingaspects, features, embodiments and advantages are merely illustrativeand are not considered elements or limitations of the appended claimsexcept where explicitly recited in a claim(s). Likewise, reference to“the invention” shall not be construed as a generalization of anyinventive subject matter disclosed herein and shall not be considered tobe an element or limitation of the appended claims except whereexplicitly recited in a claim(s).

Embodiments of the present invention generally relate to tape modules,and more specifically to fabrication of servo and data head structuresof a tape module. Referring now to FIG. 1A, a servo head 100 and a datahead 105 are formed on a substrate surface in a spaced apartrelationship according to one embodiment of the invention. It is to beunderstood that while only one servo head 100 and one data head 105 areshown, tape modules may have multiple servo heads 100 and multiple dataheads 105. For example, an array of up to thirty-two data heads 105 maybe present and bounded by two servo heads 100. Other combinations ofdata heads 105 and servo heads 100 are contemplated as well.

As shown in FIG. 1A, the servo head 100 includes a first shield layer110, a first gap layer 120 formed on the first shield layer 110, asecond gap layer 130 disposed on the first gap layer and any exposedportion of the first shield layer 110, a dielectric layer 140 formed onthe second gap layer 130 with a sensor 145 formed through the dielectriclayer, a third gap layer 150 disposed on the dielectric layer 140 andsensor 145, a fourth gap layer 160 disposed on the third gap layer 150,and a second shield layer 170 disposed on the fourth gap layer 160 andany exposed portions of the third gap layer 150.

The data head 105 is formed concurrently with the servo head 100 andincludes several layers in common, which are marked with the relatedmaterial layer deposition. For example, the first gap layer 130′ of thedata head corresponds to the second gap layer 130 of the servo head 100.

The data head 105 includes a first shield layer 110′, a first gap layer130′ conformally formed on the first shield layer 110′, a dielectriclayer 140′ formed on the first gap layer 130′ with a sensor 145′ formedthrough the dielectric layer, a second gap layer 150′ conformallydisposed on the dielectric layer 140′ and sensor 145′, and a secondshield layer 170′ disposed on the second gap layer 150′.

The first and second shield layers are each formed by anelectrodeposition process, such as electroplating or electrolessdeposition. The first and second shield layers each comprise a magneticmaterial selected from the group consisting of nickel-iron alloy,cobalt-iron alloy, cobalt-nickel-iron alloy, and combinations thereof. Anickel-iron alloy of 80 atomic percent nickel and 20 atomic percent ironmay be used as the first and second shield layer material. The firstshield layer may be formed on or in a substrate surface material ofalumina (Al₂O₃) or any other suitable material.

The first gap layer, the second gap layer, the third gap layer, and thefourth gap layer each comprise a non-magnetic material selected from thegroup consisting of an alloy of nickel and chromium, tantalum, andcombinations thereof. The first gap layer, the second gap layer, thethird gap layer, and the fourth gap layer may be deposited by a physicalvapor deposition process (PVD or sputtering) and two or more of thedeposition processes may be performed in the same chamber or sameprocessing tool. After each layer is deposited, the layer may bepatterned utilizing milling or photolithographic processing.

The first gap layer, the second gap layer, the third gap layer, and thefourth gap layer may be deposited each at a thickness from about 40 nmto about 90 nm (nanometers), however, any thickness may be used based onthe desired gap distances and sizes of the respective heads for the tapemodules. For example, the first gap layer may comprise 80 nm of NiCralloy, the second gap layer of 45 nm of NiCr alloy, the third gap layerof 45 nm NiCr alloy, and the fourth gap layer may be deposited 80 nm ofNiCr alloy.

The dielectric layer may also be deposited by a physical vapordeposition process (PVD or sputtering) and may be performed in the samechamber or same processing tool with the one or more gap depositionprocesses. The dielectric layer may comprise a suitable dielectricmaterial, such as a dielectric material selected from the group ofaluminum oxide, silicon oxide, silicon nitride, and combinationsthereof.

The first and second shield layers 110, 110′, 170, 170′ may be spacedapart by the gap layers. The servo head 100 has a greater spacingbetween shield layers 110, 170 than the data head 105 in the embodimentof FIG. 1A. In the embodiment of FIG. 1B, the spacing for the servo head100 and data head 105 may be substantially identical.

Referring now to FIG. 1B, a servo head 100 and a data head 105 areformed on a substrate surface in a spaced apart relationship accordingto one embodiment of the invention. As shown in FIG. 1B, the servo head100 includes a first shield layer 110, a first gap layer 120 formed inthe first shield layer 110, a second gap layer 130 disposed on the firstgap layer 120 and any exposed portion of the first shield layer 110, adielectric layer 140 formed on the second gap layer 130 with a sensor145 formed through the dielectric layer, a third gap layer 150 disposedon the dielectric layer 140 and sensor 145, a fourth gap layer 160disposed on the third gap layer 150, and a second shield layer 170disposed on the fourth gap layer 160 and any exposed portion of thethird gap layer 150.

The data head 105 is formed concurrently with the servo head 100 andincludes several layers in common, which are marked with the relatedmaterial layer deposition. For example, the first gap layer 130′ of thedata head corresponds to the second gap layer 130 of the servo head 100.

The data head 105 includes a first shield layer 110′, a first gap layer130′ conformally formed on the first shield layer 110′, a dielectriclayer 140′ formed on the first gap layer 130′ with a sensor 145′ formedthrough the dielectric layer, a second gap layer 150′ conformallydisposed on the dielectric layer 140′ and sensor 145′, and a secondshield layer 170′ disposed on the second gap layer 150′.

The first and second shield layers are each formed by anelectrodeposition process, such as electroplating or electrolessdeposition. The first and second shield layers each comprise a magneticmaterial selected from the group consisting of nickel-iron alloy,cobalt-iron alloy, cobalt-nickel-iron alloy, and combinations thereof. Anickel-iron alloy of 80 atomic percent nickel and 20 atomic percent Ironmay be used as the first and second shield layer material.

The first gap layer, the second gap layer, the third gap layer, and thefourth gap layer each comprise a non-magnetic material selected from thegroup consisting of an alloy of nickel and chromium, tantalum, andcombinations thereof. The first gap layer, the second gap layer, thethird gap layer, and the fourth gap layer may be deposited by a physicalvapor deposition process (PVD or sputtering) and may be performed in thesame chamber or same processing tool. After each layer is deposited, thelayer may be patterned utilizing milling or photolithographicprocessing.

The first gap layer, the second gap layer, the third gap layer, and thefourth gap layer may be deposited each at a thickness from about 40 nmto about 90 nm (nanometers), however, any thickness may be used based onthe desired gap distances and sizes of the respective heads for the tapemodules. For example, the first gap layer may comprise 80 nm of NiCralloy, the second gap layer of 45 nm of NiCr alloy, the third gap layerof 45 nm NiCr alloy, and the fourth gap layer may be deposited 80 nm ofNiCr alloy.

The dielectric layer may also be deposited by a physical vapordeposition process (PVD or sputtering) and may be performed in the samechamber or same processing tool with the one or more gap depositionprocesses. The dielectric layer may comprise a suitable dielectricmaterial, such as a dielectric material selected from the group ofaluminum oxide, silicon oxide, silicon nitride, and combinationsthereof.

FIGS. 2A-2H illustrate a series of top plan views of the steps to formthe servo head and the data head according to the embodiment of FIG. 1A.FIGS. 3A-3F illustrate a series of cross sectional views of the steps toform the servo head and the data head according to the embodiment ofFIG. 1A. The method described herein may be used for creating twodifferent shield to shield gaps on the same substrate for the servo headand the data head.

FIG. 2A illustrates a top plan view of the shaped first shield layers210 and 210′ of a servo head structure 201 of the servo head portion 203of a substrate 200 and a data head structure 202 of the data headportion 204 of the substrate 200 respectively being formed on thesubstrate 200. Line 205 represents where the formed substrate will beremoved to form an air bearing surface (ABS). FIG. 3A is a schematiccross-section view of the servo head structure 201 and a data headstructure 202 along line 205. The first shield layers 210, 210′ may eachbe deposited by an electrodeposition process, such as electroplating orelectroless deposition. The first shield layers 210, 210′ may eachcomprise a magnetic material selected from the group consisting ofnickel-iron alloy, cobalt-iron alloy, cobalt-nickel-iron alloy, andcombinations thereof. A nickel-iron alloy of 80 atomic percent nickeland 20 atomic percent iron may be used as the first shield layer 210,210′ material. Once deposited, the first shield layers 210, 210′ may befull film overcoated with a dielectric such as alumina and then chemicalmechanical polished (CMP) for planarization and minimization of thesurface roughness.

The first gap layer 220 is then formed on the servo head portion shieldlayer 210 as shown in FIG. 2B and FIG. 3B. The first gap layer 220 maycomprise a non-magnetic material selected from the group consisting ofan alloy of nickel and chromium, tantalum, and combinations thereof. Thefirst gap layer 220 may be deposited by a physical vapor depositionprocess (PVD or sputtering). The first gap layer 220 is not present onthe data head portion shield layer 210′.

In one embodiment, the first gap layer 220 may be formed by blanketdepositing first gap layer 220 material over the both first shieldlayers 210, 210′ and then patterning the deposited material. Thepatterning may comprise forming a mask over the deposited layer and themilling or etching the portions of the material not covered by the mask.The mask is then removed to leave the first gas layer 220 on the firstshield layer 210 of the servo head structure 201.

In another embodiment, the first gap layer 220 may be formed by firstdepositing a photoresist layer and developing the photoresist layer toform a mask. Thereafter, the first gap layer 220 is deposited on theexposed portions of the first shield layer 210. The mask is then removedleaving the first gap layer 220 formed over the servo head structure201. During the formation of the first gap layer 220, the sidewalls maybe tapered. The first gap layer 220 may be formed to be about 25 μm byabout 30 μm (height by width) in a shield layer of about 38 μm by 60 μm.

The second gap layer 230 of the servo head portion 203 and thecorresponding first gap layer 230′ of the data head portion 204 aredeposited on the first gap layer 220 and the exposed portion of theshaped first shield layers 210 and 210′ as shown in FIG. 2C and FIG. 3C.The second gap layer 230 and first gap layer 230′ may each comprise anon-magnetic material selected from the group consisting of an alloy ofnickel and chromium, tantalum, and combinations thereof. The materialfor the second gap layer 230 and first gap layer 230′ is selected tominimize the surface roughness of the deposited layer so that the sensor245, 245′ may be deposited thereover. If no gap layers were used and thesensors were simply deposited on the shield layers, the shield layerswould be polished to obtain a desired surface roughness. However,because the gap layers are significantly thinner than the shield layers,polishing of the gap layers may not be desirable. Therefore, the choiceof material for the gap layers will affect the surface roughness. It hassurprisingly been found that non-magnetic material selected from thegroup consisting of an alloy of nickel and chromium, tantalum, andcombinations thereof for any of the gap layers will be sufficient toobtain the desired surface roughness when deposited by a physical vapordeposition process. It has been observed that if the film roughness ofthe gap layers is sufficiently great, strong coupling between the freeand pin layers of the sensor 245, 245′ occurs that causes distortion andinstability in the readback signal. The surface roughness that isobtained utilizing the specific materials (e.g., nickel-chromium alloyor tantalum) discussed herein has been found to be sufficiently small toprevent distortion and improve stability.

The second gap layer 230 and first gap layer 230′ may be deposited by aphysical vapor deposition process (PVD or sputtering). The first gaplayer 220 and the second gap layer 230 on the servo head portion 203form a first spacer between the first shield layer 210 and the sensor245. The second gap layer 230 and first gap layer 230′ may be formed byblanket depositing the material over the substrate 200, first gap layer220, exposed portions of the first shield layer 210, and the firstshield layer 210′. Once deposited, the material is then removed fromselected portions to leave the material around the data and servo headarea.

The dielectric layer 240 and sensor 245 of the servo head portion 203and the corresponding dielectric layer 240′ and sensor 245′ (not shownin FIG. 2D) of the data head portion 204, are then formed on the secondgap layers 230 and 230′ respectively as shown in FIG. 2D and FIG. 3D.The sensors 245 and 245′ may be of any type of suitable sensor used forthe manufacturing of TMR devices. In one embodiment, the sensors 245,245′ are formed by depositing multiple material layers and then etchingback the layers, either individually or collectively, to form the finalsensors 245, 245′. The dielectric layers 240, 240′ are then formed byblanket depositing the dielectric material, forming a photoresist maskthereover, and removing the exposed dielectric material. The exposeddielectric material that is removed is formed over the sensors 245,245′. Thus, after removal of the exposed dielectric material, thedielectric material will remain everywhere except over the sensors 245,245′. The photoresist mask is then removed. Alternatively, thedielectric layers 240, 240′ may be formed by first forming a photoresistmask over the sensors 245, 245′ and then depositing the dielectriclayers 240, 240′ on the gap layers not covered by the mask. Thephotoresist mask is then removed. In an alternative embodiment, thedielectric layers 240, 240′ may be formed prior to forming the sensors245, 245′.

The third gap layer 250 of the servo head portion 203 and thecorresponding second gap layer 250′ of the data head portion 204, aredeposited on the dielectric layer 240 and sensor 245 of the servo headportion 203 and corresponding dielectric layer 240′ and sensor 245′ (notshown in FIG. 2D) of the data head portion 204, as shown in FIG. 2E andFIG. 3E. The third gap layer 250 and second gap layer 250′ may eachcomprise a non-magnetic material selected from the group consisting ofan alloy of nickel and chromium, tantalum, and combinations thereof. Thematerial for the third gap layer 250 and second gap layer 250′ isselected to minimize the surface roughness of the deposited third gaplayer 250 and second gap layer 250′ at the interface with the sensors245, 245′. The third gap layer 250 and second gap layer 250′ may bedeposited by a physical vapor deposition process (PVD or sputtering).The third gap layer 250 and second gap layer 250′ may be deposited andthen etched or milled back to the desired final shape.

After the third gap layer 250 and second gap layer 250′ are formed, thefourth gap layer 260 is deposited and patterned on the third gap layer250 of the servo head portion as shown in FIG. 2F and FIG. 3F. Thefourth gap layer 260 may comprise a non-magnetic material selected fromthe group consisting of an alloy of nickel and chromium, tantalum, andcombinations thereof. The material for the fourth gap layer 260 maycomprise the same material as the third gap layer 250. The fourth gaplayer 260 may be deposited by a physical vapor deposition process (PVDor sputtering). The fourth gap layer 260 deposition process includes thedeposition of the fourth gap layer 260 material followed by an etchingprocess, such as an ion milling process using a lithographic patterningprocess, to remove some of the fourth gap layer 260 material formingtapered sides and exposing portions of the underlying of the underlyingthird gap layer 250 material. The third gap layer 250 and the fourth gaplayer 260 form a second spacer between the second shield 270 and thesensor 245.

The second shield layer 270 of the servo head portion 203 and thecorresponding second shield layer 270′ of the data head portion 204, isdeposited on the third gap layer 250 and fourth gap layer 260 of theservo head portion 203, and the second gap portion 250′ of the data headportion 204, as shown in FIG. 2G and FIG. 3F to form the structures asshown in FIG. 1A. The second shield layers 270, 270′ may have adifferent area than the first shield layers 210, 210′. In general, thesecond shield layers 270, 270′ may each be sufficient in size to coverthe sensors 245, 245′ entirely. Each of the shield layers 210, 210′,270, 270′ may be deposited to a thickness between 0.5 μm and 2.0 μm,such as 1 μm. In order to deposit the second shield layers 270, 270′ byelectrochemical plating or electroless plating, a seed layer is firstdeposited by sputtering. The seed layer is blanket deposited. Then, thesecond shield layers 270, 270′ are deposited through a photoresist mask.The photoresist mask is then removed. The seed layer that was covered bythe mask may then be removed by an etching process.

A protective layer may be deposited over the two portions for completionof the device prior to forming the air bearing surface as shown in FIG.2H. In one embodiment, the protective layer may comprise alumina. Vias208 may be etched through the alumina layer to permit electricalconnection of the servo head portion 203 and data head portion 204 tobonding pads using high conductivity leads.

FIG. 4A is a schematic cross-section view of a servo head structure 201along line 205 according to the servo head structure of FIG. 1B. Theshaped shield layer 210 is formed on the substrate 200 as shown in FIG.4A. A feature definition 215 is formed in the shaped shield layer 210surface. The feature definition 215 may be formed by any conventionalprocess, such as ion milling, and is preferably formed with tapered(from the bottom to top of the feature definition) or vertical sides.The feature definition 215 is milled to a targeted depth.

The first gap layer 220 material is deposited in the feature definition215 with a thickness equal to the targeted depth of the featuredefinition 215. The formation of the feature definition 215 and thedeposition of the first gap layer 220 may occur utilizing the samephotolithographic mask. For example, after the shield layer 210 isdeposited on a substrate 200, a photolithographic mask is formed bydepositing a photoresist and then developing the photoresist to form themask. The shield layer 210 is then selectively milled or etched usingthe mask so that the feature definition 215 is formed. Then, utilizingthe same mask, the first gap layer 220 is deposited into the featuredefinition 215. The mask and any of the first gap layer that isdeposited thereon is then removed.

The second gap layer 230 is conformally deposited on the planar surfaceof the first shield layer 210 and the first gap layer 220 as shown inFIG. 4C. The dielectric layer 240 and sensor 245 are deposited,patterned, and formed on the second gap layer 230 as shown in FIG. 4D.The third gap layer 250 is conformally deposited on the dielectric layer240 and sensor 245 as shown in FIG. 4E.

The fourth gap layer 260 is deposited and patterned on the third gaplayer 250 as shown in FIG. 4F. The fourth gap layer 260 depositionprocess includes the deposition of the fourth gap layer 260 materialfollowed by an etching process, such as an ion milling process using alithographic patterning process, to remove some of the fourth gap layer260 material forming tapered ends and exposing portions of theunderlying of the underlying third gap layer 250 material.

The second shield layer 270 is deposited on the third gap layer 250 andfourth gap layer 260, as shown in FIG. 4F to form the servo headstructure as shown in FIG. 1B. The data head structure of FIG. 1B isformed as described above for the data head structure of FIG. 1A.

By utilizing electrically conductive gap layers between shield layers inboth the servo head and data head of a tape module, the tape module maybe effective and be capable of utilizing a TMR sensor. The gap layersmay comprise tantalum, an alloy of nickel and chromium, or combinationsthereof. The material of the gap layers is beneficial because the gaplayers will have an acceptable surface roughness without polishing, andpolishing the gap layers may not be possible due to relatively smallthickness of the gap layers.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

What is claimed is:
 1. A method for forming a tape module, comprising:forming a servo head structure on a substrate, comprising: depositing afirst servo head shield layer on the substrate, the first servo headshield layer having a feature definition formed therein, wherein thefeature definition has a milled targeted depth; depositing a firstelectrically conductive servo head gap layer on the first servo headshield layer, wherein the first electrically conductive servo head gaplayer is formed within the first servo head shield layer featuredefinition and has a thickness equal to the feature definition milledtargeted depth; depositing a second electrically conductive servo headgap layer on the first electrically conductive servo head gap layer;forming a servo head sensor on the second electrically conductive servohead gap layer; depositing a servo head dielectric layer on the secondelectrically conductive servo head gap layer, wherein the servo headsensor is formed through the servo head dielectric layer and wherein thesensor has a bottom face only in contact with the second electricallyconductive servo head gap layer, a top face only connected to a thirdelectrically conductive servo head gap layer and a side only connectedto the servo head dielectric layer; depositing the third electricallyconductive servo head gap layer on the servo head dielectric layer andservo head sensor; depositing a fourth electrically conductive servohead gap layer on the third electrically conductive servo head gaplayer; and depositing a second servo head shield layer on the fourthelectrically conductive servo head gap layer.
 2. The method of claim 1,further comprising etching the feature definition into the first servohead shield layer and depositing the first electrically conductive servohead gap layer in the feature definition.
 3. The method of claim 1,further comprising: forming a data head structure on the substrate,comprising: depositing a first data head shield layer on the substrate;depositing a first data head gap layer on the first data head shieldlayer; forming a data head sensor on the first data head gap layer;depositing a data head dielectric layer on the first data head gaplayer; depositing a second data head gap layer on the data headdielectric layer and data head sensor; and depositing a second data headshield layer on the second data head gap layer.
 4. The method of claim3, wherein the third electrically conductive servo head gap layer andthe second data head gap layer are deposited during the same depositionprocess.
 5. The method of claim 3, each of the first electricallyconductive servo head gap layer, the second electrically conductiveservo head gap layer, the third electrically conductive servo head gaplayer, the fourth electrically conductive servo head gap layer, thefirst data head gap layer, and the second data head gap layer aredeposited by a sputtering process.
 6. The method of claim 5, wherein thefirst electrically conductive servo head gap layer, the secondelectrically conductive servo head gap layer, the third electricallyconductive servo head gap layer, the fourth electrically conductiveservo head gap layer, the first data head gap layer, and the second datahead gap layer each comprise a non-magnetic material selected from thegroup consisting of an alloy of nickel and chromium, tantalum, andcombinations thereof.
 7. The method of claim 6, wherein the secondelectrically conductive servo head gap layer and the first data head gaplayer are deposited during the same deposition process.
 8. The method ofclaim 7, wherein the first data head shield layer, the second data headshield layer, the first servo head shield layer, and the second servohead shield layer each comprise a magnetic material selected from thegroup consisting of nickel-iron alloy, cobalt-iron alloy,cobalt-nickel-iron alloy, and combinations thereof.
 9. The method ofclaim 8, wherein the first data head shield layer, the second data headshield layer, the first servo head shield layer, and the second servohead shield layer are each deposited by an electroplating process. 10.The method of claim 9, further comprising depositing a seed layer overthe fourth electrically conductive servo head gap layer and the seconddata head gap layer prior to depositing the second servo head shieldlayer and the second data head shield layer.
 11. A method for forming atape module, comprising: forming a servo head structure on a substrate,comprising: depositing a first servo head shield layer on the substrate,the layer having a feature definition with a depth; depositing a firstconductive servo head gap layer on the first servo head shield layerwith a thickness equal to the feature definition depth, wherein thefirst conductive servo head gap layer is formed within the first servohead shield layer feature definition; depositing a second conductiveservo head gap layer on the first conductive servo head gap layer;forming a servo head sensor on the second conductive servo head gaplayer; depositing a servo head dielectric layer on the second conductiveservo head gap layer, wherein the servo head sensor is formed throughthe servo head dielectric layer and wherein the servo head sensor has abottom face only in contact with the second conductive servo head gaplayer, a top face only connected to a third conductive servo head gaplayer and a side only connected to the servo head dielectric layer;depositing the third conductive servo head gap layer on the servo headdielectric layer and the servo head sensor; depositing a fourthconductive servo head gap layer on the third conductive servo head gaplayer; and depositing a second servo head shield layer on the fourthconductive servo head gap layer.
 12. The method according to claim 11,wherein the first conductive servo head gap layer, the second conductiveservo head gap layer, the third conductive servo head gap layer and thefourth conductive servo head gap layer comprise at least one oftantalum, an alloy of nickel and chromium.
 13. The method according toclaim 11, wherein the first and the second servo head shield layers areformed through an electrodeposition process.
 14. The method according toclaim 11, wherein the first and the second servo head shield layers areformed through electroless deposition.
 15. A method for forming a tapemodule, comprising: forming a servo head structure on an aluminasubstrate, comprising: depositing a first servo head shield layer one ofon and in the substrate, the first servo head shield layer having afeature definition formed therein, wherein the feature definition has adepth; depositing a first electrically conductive servo head gap layeron the first servo head shield layer, wherein the first electricallyconductive servo head gap layer is formed within the first servo headshield layer feature definition and has a thickness equal to the featuredefinition depth; depositing a second electrically conductive servo headgap layer on the first electrically conductive servo head gap layer;forming a servo head sensor on the second electrically conductive servohead gap layer; depositing a servo head dielectric layer on the secondelectrically conductive servo head gap layer, wherein the servo headsensor is formed through the servo head dielectric layer and wherein theservo head sensor has a bottom face only in contact with the secondelectrically conductive servo head gap layer, a top face only connectedto a third electrically conductive servo head gap layer and a side onlyconnected to the servo head dielectric layer; depositing the thirdelectrically conductive servo head gap layer on the servo headdielectric layer and the servo head sensor; depositing a fourthelectrically conductive servo head gap layer on the third electricallyconductive servo head gap layer; and depositing a second servo headshield layer on the fourth electrically conductive servo head gap layer.16. The method according to claim 15, wherein the first electricallyconductive servo head gap layer, the second electrically conductiveservo head gap layer, the third electrically conductive servo head gaplayer and the fourth electrically conductive servo head gap layercomprise at least one of tantalum, an alloy of nickel and chromium. 17.The method according to claim 15, wherein at least one of the first andthe second electrically conductive servo head gap layer are formedthrough physical vapor deposition.
 18. The method according to claim 15,wherein at least one of the third and the fourth electrically conductiveservo head gap layer are formed through physical vapor deposition. 19.The method according to claim 15, wherein the first and the second servohead shield layers are formed through an electrodeposition process. 20.The method according to claim 15, wherein the first and the second servohead shield layers are formed through electroless deposition.